Platform structure and construction method

ABSTRACT

A railway station platform structure is constructed by: (a) constructing foundations ( 36 ) alongside the railway: (b) constructing up-standing supporting members ( 37 ) on the foundations ( 36 ); (c) mounting cross beams ( 38 ) on the supporting members ( 37 ) so that the cross beams have cantilevered extending beyond the supporting members ( 37 ) towards the railways, (d) mounting longitudinal beams ( 42 ) on the cross beams ( 38 ); and (e) mounting platform units ( 1 ) on the longitudinal beams ( 42 ) so that side edge surfaces of the units extend away from the railway and front edge surfaces of the units extend along the railway beyond the ends of the cantilevered portion of the cross beams ( 38 ).

[0001] This invention relates to the construction of platforms for railway stations.

[0002] The increasing demand for rail travel is requiring train operating companies to create extra capacity by the use of longer trains, but manly existing station platforms are too short to accommodate such trains. The construction of platform extensions is restricted by the requirement to minimise disruption to normal use of the existing platform, to accommodate the works within existing train service patterns, and to have possession of the track while much of the construction work is carried out.

[0003] It would therefore be desirable to be able to minimise the time for which track possession is required when constructing a railway station platform. In particular it would be desirable to be able to provide a structure which can be constructed quickly, without using time-consuming processes during possession.

[0004] In one aspect the invention provides a railway station platform structure comprising foundations alongside the railway; upstanding supporting members rising from the foundations; cross beams mounted on the supporting members and having cantilevered portions extending beyond the supporting members towards the railway; longitudinal beams on the cross beams, each longitudinal beam extending between a pair of the cross beams, there being at least two longitudinal beams between each pair of cross beams, at least one of these longitudinal beams being on the cantilevered portions of the cross beams and at least one of these longitudinal beams being remote from the cantilevered portions; and platform units on the longitudinal beams, the platform units shaking side edge surfaces extending away from the railway and having front edge surfaces extending along the railway beyond the ends of the cantilevered portions of the cross beams.

[0005] In another aspect the invention provides a method of constructing a railway station platform structure, including the steps of:

[0006] (a) constructing foundations alongside the railway,

[0007] (b) constructing upstanding supporting members on the foundations; and

[0008] (c) mounting on the supporting members a prefabricated superstructure comprising cross beams mounted on the supporting members so that the cross beams have cantilevered portions extending beyond the supporting members towards the railway, longitudinal beams on the cross beams, and platform units on the longitudinal beams, side edge surfaces of the units extending away from the railway and front edge surfaces of the units extending along the railway beyond the ends of the cantilevered portions of the cross beams.

[0009] In another aspect the invention provides a method of constructing a railway station platform structure, including the following steps:

[0010] (a) constructing foundations alongside the railway;

[0011] (b) constructing upstanding supporting members on the foundations;

[0012] (c) mounting cross beams on the supporting members so that the cross beams have cantilevered portions extending beyond the supporting members towards the railway;

[0013] (d) mounting longitudinal beams on the cross beams; and

[0014] (e) mounting platform units on the longitudinal beams so that side edge surfaces of the units extend away from the railway and front edge surfaces of the units extend along the railway beyond the ends of the cantilevered portions of the cross beams.

[0015] The invention will be described further, by way of example only, with reference to the accompanying drawings, in which:

[0016]FIG. 1A is an exploded isometric view of edge copers and tactile paving elements for use in the construction of the platform;

[0017]FIG. 1 is an isometric view of three prefabricated platform units slab units, for use in the construction of a platform;

[0018]FIG. 2 is a vertical section through a platform structure incorporating the slab units of FIG. 1, in a first embodiment;

[0019]FIG. 3 is an exploded isometric view of the first embodiment of the platform structure;

[0020]FIG. 4 is a vertical section through a second embodiment of the platform structure; and

[0021]FIG. 5 is an exploded isometric view of the second embodiment of the platform structure.

[0022] Each prefabricated platform unit or slab unit 1, shown in FIGS. 1 to 3, is a pre-cast concrete unit incorporating a reinforcing mesh 2 (not shown). The slab unit 1 has a mostly planar bottom surface 3 and a stepped upper surface 4. The slab unit has a nominal width of 2 metres (for example) and has a rectangular outline when viewed from above. In general, the length of the slab unit from its front edge to its rear edge is at least equal to its width. Exemplary dimensions, in millimetres, are indicated in FIG. 3. The slab unit has a front edge surface 6, a rear edge surface 7, and side edge surfaces 8,9, all of which are vertical surfaces. The upper surface 4 has a rebated forward portion 4 a which is planar and parallel to the bottom surface 3, a rearward portion 4 b which is planar and slopes downwardly and rearwardly from its front edge to its rear edge, and a step 4 c which rises vertically between the forward and rearward portions 4 a, 4 b. The step 4 c extends across the width of the slab unit, parallel to its front edge surface 6.

[0023] The platform units or slab units 1 illustrated are longer from front to back than their individual width and are used in the construction of a new platform structure, which may be an extension to an existing platform structure. The rearward portion 4 b of the upper surface 4 has a gradual slope (1 in 50) from front to back, and there is a raised plinth 27 near the rear edge surface 7 of the slab unit 1. A drainage outlet 28 is provided in the front surface of the plinth 27. One side edge surface 9 has a key formation 29 for fitting in a recess or groove 31 in the opposite side edge surface 8 of an adjacent slab unit so as to prevent relative vertical movement of the adjacent slab units. The bottom surface of the slab unit 1 has integrally cast projections 32 for a purpose to be explained below. One slab unit 1 has a recess 33 in one edge, for receiving a lighting column (not shown).

[0024] A first embodiment of a platform structure incorporating the slab units 1 shown in FIG. 1 will now be described with reference to FIGS. 2 and 3, by describing the steps involved in its method of construction.

[0025] (1) Simple temporary mesh fencing 34 is set up at a spacing of 2 metres from the centre line of the outermost track rail 24 to define a border between the so-called red zone (in which it would be hazardous and, in some situations, not permitted to work when not in track possession) and the so-called green zone (in which it is safe to work under certain conditions, whether or not in track possession).

[0026] (2) In the green zone the ground is prepared and excavated to provide two trenches parallel to the track. Concrete is then poured into the trenches to form strip foundations 36.

[0027] (3) In situ concrete support columns 37 are constructed on the strip foundations 36 and incorporate vertically projecting corrosion resistant threaded tie bars of 16 mm diameter (not shown in FIG. 8).

[0028] (4) Pre-cast concrete cross beams 38 are craned in and positioned on the support columns 37. Each cross beam 38 is supported by two columns 37 and has a cantilevered portion 38 a extending beyond the support columns 37 towards the track Each cross beam 38 has two vertical through holes 39, which are formed during the casting of the concrete cross beam and which have a minimum diameter of 50 mm. These oversize holes 39 receive the threaded bars projecting upwards from the columns 37 and are used to locate the cross beams 38 relative to the support columns 37, nuts being threaded on the tie bars to provide a mechanical connection between the cross beam 38 and the support columns 37. Resilient rubber pads (not shown) with pre-formed holes to receive the threaded bars are located on top of the columns 37. The cross beams 38 incorporate holding down bolts (not shown) for connecting the base of the lighting column and one or more ducts 41 for the passage of electrical cables.

[0029] (5) Pre-cast longitudinal beams 42 are craned in and mounted on the cross beams 38. The upper edges of the cross beams 38 have recesses 43 which accommodate end portions 42 a of the beams 42 resting on resilient rubber pads 44 at the bottoms of the recesses 43. Abutment surfaces 42 b (recessed beneath the end portions 42 a) face the respective side surfaces of the cross beams 38. The upper surfaces of the cross beams 38 are flush with the upper surfaces of the longitudinal beams 42.

[0030] (6) The slab units 1 are craned in and mounted on the supporting structure constituted by the cross beams 38 and longitudinal beams 42. The downward projections 32 on the slab units abut against respective side surfaces of two of the longitudinal beams 42 to locate the slab units in the direction towards and away from the track The slab units 1 are installed one by one, engaging the key formation 29 on each slab unit with the corresponding groove 31 of the next slab unit. The joints between adjacent units are sealed by a dry rubber O-ring which, when compressed, forms a watertight seal. To assist installation, temporary lifting fins (not shown) can be fitted to anchorages (not shown) located in or near the plinth 27 and in the forward portion 4 a of the upper surface of the slab unit.

[0031] (7) Platform fencing (not shown) is erected on the plinths 27 and electrical cabling is installed using the cable ducts 41 and cable support trays 46 mounted in facing longitudinal recesses 47 in a pair of the longitudinal beams 42.

[0032] (8) Platform lighting is installed, a lighting column being inserted through the recess 33 in at least one of the slab units 1 and bolted to the cross beam 38 below.

[0033] (9) Lightweight edge copers 23 (FIG. 1A) are installed on quick-setting epoxy adhesive mortar on the forward portions 4 a of the upper surface 4 of the slab units 1. In the present example five edge copers 23 are mounted side by side across the two metre width of each slab unit. Depending on the size of the edge copers, more or fewer may be used, although there are preferably at least four. Accordingly, the edge copers 23 are small enough to be handled without undue strain, preferably weighing at most 25 kg if they are made of pre-cast concrete and being substantially lighter if they are made of less dense materials, for example plastics material The edge copers 23 overlap the front edge of the slab unit I and are laid level so that their front edges are at a given horizontal and vertical spacing from the adjacent rail 24.

[0034] (10) Tactile paving elements 26 (which can be felt by a person's foot) are installed on quick-setting epoxy adhesive mortar, between the edge copers 23 and the step 4 c, in such a manner as to compensate for any difference in level between the rear edges of the edge copers 23 and the front edge of the rearward portion 4 b of the upper surface of the slab unit.

[0035] (11) Anti-debris netting (not shown) is installed beneath the platform, by means of stainless steel eyes received in sockets (not show) cast in the cross beams 38.

[0036] (12) Finally the temporary fencing 34 is removed.

[0037] It will be appreciated that steps (2), (3), (7), and (11) do not require track possession The design of the platform structure ensures that the other steps, which will normally require track possession, can be carried out quickly and in separate stages.

[0038] A second embodiment of the platform structure will now be described with reference to FIGS. 4 and 5. The second embodiment differs from the first embodiment only in using piles instead of strip foundations. Accordingly, the above description, except for step (2), is applicable to the second embodiment and will not be repeated.

[0039] In the construction of the second embodiment, step (2) is replaced by the step of preparing the ground and inserting piles 36 a into the ground at the intended locations of the supporting columns 37, which are subsequently constructed on the piles.

[0040] Various modifications may be made within the scope of the invention In particular, the lengths of the cross beams 38 and the number of longitudinal beams 42 between each pair of cross beams may be varied to suit different platform widths (front to back). For a platform width of less than 3 metres (for example 2.5 metres) two longitudinal beams 42 may be sufficient. For platform widths of 3 or 3.5 metres, three longitudinal beams 42 may be sufficient. For a platform width of 4 metres, four longitudinal beams should be used. The position of the front longitudinal beam in relation to the front end of the cross beam will be the same in each case, so that pre-cast concrete manufacture of the cross beams can to some extent be standardised.

[0041] To accommodate curved track alignments the side edges of one or more of the slab units may be non-parallel, either converging or diverging away from the front edge, one or both of the side edges not being perpendicular to the front edge.

[0042] Cable-tray receiving grooves 47 may be provided in more than two of the longitudinal beams 42, and additional holes 41 may be provided in the cross beams 38 if one or more additional cable trays are fitted using these grooves.

[0043] To simplify construction of the superstructure on the support columns 37, the platform units 1 may be combined with the longitudinal beams 42 as prefabricated units, or longitudinal and cross beams may be combined as prefabricated units, or platform units and longitudinal and cross beams may be combined as prefabricated units. In each case the spacing of the supporting columns 37 would be reduced by approximately one half, the width of the prefabricated units being correspondingly reduced in order to keep the weight to be lifted within practicable limits.

[0044] Instead of fitting the edge copers and tactile paving elements on the slab units after the installation of the slab units, it may be possible to fit them on the slab units before the slab units are mounted on the supporting structure. It may also be possible to combine the tactile paving elements with the edge copers, or to omit the tactile paving elements.

[0045] Furthermore, it may be possible for the edge copers and tactile paving elements to be omitted and for the upper surface of the slab unit to be provided with a suitably textured finish. In this case, the rebated forward portion may be omitted or reduced in size to receive a relatively narrow edging strip (e.g. of stainless steel) set in epoxy mortar for example.

[0046] The platform structure can be provided at any trackside location where it may be desired to bring a train to a halt in order to allow passengers or train operating staff to board or alight from the train or to attend to the maintenance of the exterior of the train. 

1. A railway station platform structure comprising: foundations alongside the railway; upstanding supporting members rising from the foundations; cross beams mounted on the supporting members; longitudinal beams, each longitudinal beam extending between a pair of the cross beams, there being at least two longitudinal beams between each pair of cross beams, platform units on the longitudinal beams, the platform units having side edge surfaces extending away from the railway and having front edge surfaces extending along the railway beyond the front ends of the cross beams the cross beams, the longitudinal beams, and the platform units being separate from one another: the cross beams having cantilevered portions extending beyond the supporting members towards the railway; and at least one of the longitudinal beams which extends between a pair of the cross beams being mounted on the cantilevered portions of those cross beams and at least one of these longitudinal beams being mounted on these cross beams at a position remote from the cantilevered portions.
 2. A platform structure as claimed in claim 1, in which the supporting members comprise columns.
 3. A platform structure as claimed in claim 1, in which each cross beam is supported by two said supporting members.
 4. A platform structure as claimed in claim 1, in which the supporting members and the cross beams have complementary formations which interengage to locate the cross beams relative to the supporting members.
 5. A platform structure as claimed in claim 4, in which the said formations on the supporting members comprise tie bars and the said formations on the cross beams comprise through-holes.
 6. A platform structure as claimed in claim 1, in which the cross beam are connected to the supporting members solely by mechanical connection devices.
 7. A platform structure as claimed in claim 1, in which the cross beams have upwardly and laterally open recesses which accommodate end portions of the longitudinal beams.
 8. A platform structure as claimed in claim 7, in which resilient pads are interposed between the said end portions and the bottoms of the said recesses.
 9. A platform structure as claimed in claim 7 or 8, in which the longitudinal beams have end abutment surfaces recessed beneath the said end portions.
 10. (canceled)
 11. A platform structure as claimed in claim 1, in which the upper surfaces of the cross beams are substantially flush with the upper surfaces of the longitudinal beams.
 12. A platform structure as claimed in claim 1, in which at least one pair of adjacent longitudinal beams, between an adjacent pair of cross beams, have longitudinal recesses which face each other, for receiving a cable support tray.
 13. A platform structure as claimed in claim 1, in which at least one of the cross beams has at least one transverse aperture for the passage of a cable.
 14. A platform structure as claimed in claim 1, in which each platform has a stepped upper surface comprising a forward portion and a rearward portion, with a step rising between the forward and rearward portions, the forward portion being planar.
 15. A platform structure as claimed in claim 14, in which the rearward portion of the upper surface slopes downwardly and rearwardly from adjacent the step.
 16. A platform structure as claimed in claim 1, in which each platform unit is made of reinforced concrete.
 17. A platform structure as claimed in claim 1, in which the length of each platform unit from front to rear is at least as great as its width.
 18. A platform structure as claimed in claim 1, in which each platform unit is about 2 metres wide.
 19. A platform structure as claimed in claim 1, in which the undersides of the platform units have projections for locating the platform units relative to the longitudinal beams.
 20. A platform as claimed in claim 1, in which each longitudinal beam supports at least two platform units.
 21. (canceled)
 22. A platform structure as claimed in claim 1, in which the adjacent side edge surfaces of adjacent platform units have, respectively, a key formation and a recess in which the key formation fits so as to resist relative vertical motion of the adjacent platform units.
 23. A platform structure as claimed in claim 1, in which each platform unit is elongate in the direction away from the railway.
 24. A platform structure as claimed in claim 1, in which the platform units include raised portions which are aligned to constitute a plinth to the rear of the platform structure.
 25. A platform structure as claimed in claim 1, further comprising edge copers mounted side by side on the platform units. 26-28. (canceled)
 29. A method of constructing a railway station platform structure, including the following steps: (a) constructing foundations alongside the railway; (b) constructing upstanding supporting members on the foundations; (c) mounting cross beams on the supporting members so that the cross beams have cantilevered portions extending beyond the supporting members towards the railway; (d) mounting longitudinal beams on the cross beams; and (e) mounting platform units on the longitudinal beams so that the side edge surfaces of the units extend away from the railway and the front edge surfaces of the units extend along the railway beyond the ends of the cantilevered portions of the cross beams.
 30. A method as claimed in claim 29, further comprising the step of mounting edge copers on a rebated forward portion of the upper surface of the units.
 31. A method as claimed in claim 30, in which there are at least four edge copers, mounted side by side per unit.
 32. A method as claimed in claim 30, in which the width of each edge coper is less than its length.
 33. A method as claimed in claim 30, in which each edge coper weighs at most 25 kg.
 34. A method as claimed in claim 30, in which the edge copers are installed on a quick-setting resin-based mortar.
 35. A method as claimed in claim 30, further comprising the step of installing paving elements between the edge copers and a step in the upper surface of the unit. 